CN102220579B - Brush-coat type phosphating solution containing rust and preparation method thereof - Google Patents

Abstract

A brushing type rusty phosphating solution and a preparation method thereof relate to a phosphating solution. Provide a clean and pollution-free, fast film-forming, strong binding force, good corrosion resistance, easy operation, low investment, low cost, etc., and is suitable for large workpieces or outdoor equipment, oil removal, rust removal, phosphating 1. Brushing type rusty phosphating solution with passivation completed in one step and preparation method thereof. Brushing type rusty phosphating solution is composed of the following raw materials: phosphoric acid, zinc oxide, ethylenediaminetetraacetic acid, ethanol, sodium molybdate, sodium fluoride, nickel sulfate, polyethylene glycol 6000, and the balance is water. Add zinc oxide into a small amount of water to make a paste; then add phosphoric acid, dissolve and add ethylenediaminetetraacetic acid, then add ethanol, sodium molybdate, nickel sulfate (or nickel acetate) and polyethylene glycol 6000 in sequence, and stir well Then add enough water to get the brushing type rusty phosphating solution.

Description

A kind of brushing type rusty phosphating solution and preparation method thereof

technical field

The invention relates to a phosphating solution, in particular to a brushing type rusty phosphating solution and a preparation method thereof.

Background technique

In order to improve the anti-rust ability of the surface of steel parts, the surface is usually phosphating. Phosphating film is mainly used as the bottom layer of paint coating, the lubricating layer of metal cold processing, and the protective layer of metal surface, etc., which can play various functions such as rust prevention, wear reduction, lubrication, and improvement of adhesion between paint and metal substrate.

The phosphating process for iron and steel parts is mostly medium-high temperature phosphating, which requires degreasing and rust pretreatment before treatment, and the temperature is high, energy consumption is high, phosphating time is long, and the process is complicated. In addition, the most commonly used methods of phosphating are spraying or soaking. With the expansion of the application field of phosphating, these methods can no longer adapt to the new situation. For example, the phosphating of some steel equipment in the fields of construction, electric power, offshore oil exploitation, metallurgy and mining is not suitable for spraying or immersion because of its large volume, weight and complex structure. At present, the development direction of phosphating technology is mainly to improve quality and reduce pollution, energy saving, non-toxic, and environmental protection, and further clean phosphating. Phosphating solution should save materials and energy, and have reasonable functions. It will not endanger human health and destroy the ecological environment. Therefore, a rapid and multifunctional phosphating process at room temperature needs to be solved urgently. Adhesion and corrosion resistance can be greatly improved; "multifunctional" means that it has the characteristics of one-step completion of oil removal, rust removal, phosphating, and passivation, which can greatly save procedures and simplify operations; in addition, the brushing operation does not require acid The tank can greatly increase the application field of the process, especially suitable for phosphating treatment of large workpieces or outdoor equipment.

Contents of the invention

The purpose of the present invention is to provide a method that not only has the advantages of clean and pollution-free, fast film formation, strong binding force, good corrosion resistance, easy operation, less investment, and low cost, but also is suitable for large workpieces or outdoor equipment, degreasing, The invention relates to a brushing type rusty phosphating solution which can complete rust removal, phosphating and passivation in one step and a preparation method thereof.

The brushing type rusty phosphating solution is composed of the following raw materials:

Phosphoric acid 1392～208.8mL/L;

Zinc oxide 1～3g/L;

Ethylenediaminetetraacetic acid (EDTA) 4～10g/L;

Ethanol 126.6mL/L;

Sodium molybdate 1.5～4g/L;

Sodium fluoride 1～3g/L;

Nickel sulfate (or nickel acetate) 1～2g/L;

Polyethylene glycol 6000 2～5g/L;

The balance is water.

The preparation method of described brushing type rusty phosphating solution comprises the following steps:

1) Add zinc oxide into a small amount of water to make a paste;

2) Add phosphoric acid, add ethylenediaminetetraacetic acid after dissolving, then add ethanol, sodium molybdate, nickel sulfate (or nickel acetate) and polyethylene glycol 6000 in sequence, stir evenly, add sufficient water to obtain the coating Brush type rust phosphating solution.

The using method of the brushing type rusty phosphating solution is:

1) Pretreatment of steel parts

Ordinary rusted steel parts do not require pre-treatment. For steel parts with a large amount of rust, sandpaper or steel can be used to remove excessive rust shells and floating ash.

2) Phosphating treatment of steel parts

Use an acid-resistant brush to directly apply a layer of phosphating solution evenly on the iron piece, and then wait for it to dry naturally.

The phosphating film formed by the brushing type rusty phosphating solution of the present invention is black, bright and compact, with a thickness of up to 100 μm and good binding force. The CuSO ₄ drip test is tested according to the regulations in GB/T 6807-1986. The time required for the droplet to turn into light red can reach 470s; the medium-sized salt spray test shall be tested according to the provisions of GB/T 10125-1997, and there will be no rust marks for more than 12 hours.

Experiment proves that the formed phosphating film after the brushing type rust phosphating solution treatment of the present invention shows the film structure containing cracks on the surface, and this structure shows its unique characteristics when it is used as the coating bottom layer. Superiority, through the penetration of the paint into the cracks, the bite between the paint and the phosphating film, the adhesion of the paint film is effectively improved. Tested according to the provisions of GB-T1720-1979, the adhesion of the paint film is not less than grade 1.

Description of drawings

Fig. 1 is an SEM image of the surface morphology of the phosphating film after being treated with the brushing type rusty phosphating solution described in the embodiment of the present invention. In Figure 1, the scale bar is 20 μm.

Detailed ways

Example 1

The brushing type rusty phosphating solution of the present invention is made up of following raw material:

Phosphoric acid 174mL/L;

Zinc oxide 1.6g/L;

EDTA 6g/L;

Ethanol 126.6mL/L;

Sodium molybdate 1.5g/L;

Sodium fluoride 1g/L;

Nickel sulfate 2g/L;

Polyethylene glycol 6000 2g/L;

Water balance.

Add zinc oxide into a small amount of water to make a paste, then add phosphoric acid and stir until fully dissolved. Add EDTA and stir until fully dissolved. Then add ethanol, sodium molybdate, nickel sulfate, polyethylene glycol 6000 in turn, stir evenly, and finally add enough water. The iron door with serious rust is treated by brushing, the film forming effect is good, the film layer is bright black, and the paint film has good adhesion.

Example 2

The brushing type rusty phosphating solution of the present invention is made up of following raw materials:

Phosphoric acid 208.8mL/L;

Zinc oxide 1g/L;

EDTA 10g/L;

Ethanol 126.6mL/L;

Sodium molybdate 2.5g/L;

Sodium fluoride 3g/L;

Nickel sulfate 1.5g/L;

Polyethylene glycol 6000 4g/L;

Water balance.

The preparation method of phosphating solution is the same as in Example 1. It is operated by brushing to deal with the iron ship hull with serious rust, the effect is good, the film layer is bright black, and the bonding force is strong.

Example 3

The brushing type rusty phosphating solution of the present invention is made up of following raw material:

Phosphoric acid 139.2mL/L;

Zinc oxide 3g/L;

EDTA 4g/L;

Ethanol 126.6mL/L;

Sodium molybdate 2g/L;

Sodium fluoride 1.5g/L;

Nickel acetate 2g/L;

Polyethylene glycol 6000 3g/L;

Water balance.

The preparation method of phosphating solution is the same as in Example 1. It is operated by brushing to deal with the iron bracket with serious rust. The effect is good, the film layer is bright and black, and the bonding force is strong.

Example 4

The brushing type rusty phosphating solution of the present invention is made up of following raw materials:

Phosphoric acid 139.2mL/L;

Zinc oxide 2.5g/L;

EDTA 8g/L;

Ethanol 126.6mL/L;

Sodium molybdate 4g/L;

Sodium fluoride 2.5g/L;

Nickel acetate 1g/L;

Polyethylene glycol 6000 5g/L;

Water balance.

The preparation method of phosphating solution is the same as in Example 1. It is operated by brushing to deal with the iron casing of the agricultural threshing machine with serious rust. The effect is good, the film layer is black and bright, and the hardness is high.

As can be seen from Fig. 1, the formed phosphating film after the brushing type rust phosphating solution treatment of the present invention shows the film structure containing cracks on the surface, and this structure shows its properties when it is used as the coating bottom layer. Unique superiority, through the penetration of the paint into the cracks, the bite between the paint and the phosphating film, the adhesion of the paint film is effectively improved. Tested according to the provisions of GB-T1720-1979, the adhesion of the paint film is not less than grade 1.

Claims (2)

1. a brush-coat type phosphating solution containing rust, is characterized in that its raw material consists of:

2. the preparation method of a kind of brush-coat type phosphating solution containing rust as claimed in claim 1, is characterized in that comprising the following steps:

1) zinc oxide is added in a small amount of water, furnishing pasty state;

2) add phosphoric acid again, after dissolving, add ethylenediamine tetraacetic acid (EDTA), then add ethanol successively, Sodium orthomolybdate, single nickel salt or nickelous acetate, polyethylene glycol 6000, add enough water after stirring and namely obtain described brush-coat type phosphating solution containing rust.